This paper deals with the stability of nite di erence approximations of initial value problems for the wave equation with absorbing boundary conditions. The stability of a family of high order variational numerical schemes is studied by energy techniques. Dirichlet, sponge and rst order paraxial absorbing boundary conditions are treated. The variational form of the schemes as well as the use of...

Imitating the natural "energy cascade" architecture, we present a single-molecular rod-like nano-light harvester (NLH) based on a cylindrical polymer brush. Block copolymer side chains carrying (9,9-diethylfluoren-2-yl)methyl methacrylate units as light absorbing antennae (energy donors) are tethered to a linear polymer backbone containing 9-anthracenemethyl methacrylate units as emitting group...

Material properties and geometry are two important design parameters which their effects should be considered in a crashworthiness analysis. In this paper, the axial impact of metallic and hybrid energy absorbing thin-walled tubes with poly-gonal cross-section is simulated using LS-DYNA software. The combined effects of changing the geometry and material properties on the mass specific energ...

In atomic and molecular spectroscopy, measured transition energies represent diierences between the energy levels of the emitting or absorbing system. In complex spectra of such transitions the identiication of the pair of states corresponding to an observed transition energy is a diicult process. The assignment of transition energies to energy levels proceeds in stages. At each stage, some ide...

In this paper a review of impact mechanics and high-energy absorbing materials is presented. We review different theoretical models (rigid-body dynamics, elastic, shock, and plastic wave propagation, and nonclassical or nonlocal models. and computational methods (finite-element, finite-difference, and mesh-free methods. used in impact mechanics. Some recent developments in numerical simulation ...

A lightweight energy-absorbing keel-beam concept was developed and retrofitted in a general aviation type aircraft to improve crashworthiness performance. The energy-absorbing beam consisted of a foam-filled cellular structure with glass fiber and hybrid glass/kevlar cell walls. Design, analysis, fabrication and testing of the keel beams prior to installation and subsequent fullscale crash test...

This paper concerns the absorption of energy from two-dimensional water waves propagating over fluid constant depth by a wave converter consisting small buoyant floating rafts constrained to move in heave motion and attached bed with springs dampers. Under shallow approximation motion, it is shown that spatially-varying spring damper settings allow all be absorbed frequencies. The basis design ...